Did You Know...
You can download the coverage and tile boundaries for all the data you find on MapWarehouse? A great feature for frequent users, yet less than 2% of customers are taking advantage of it.
- Free and unlimited
- Choose KML (for Google Earth) or SHP (for ArcGIS)
- Estimate your data requirements
- Order faster and more efficiently
As you know, most mapping data and imagery found on MapWarehouse cover large geographic areas. The coverage is clipped into 500m x 500m tiles based on a common grid, which enables you to purchase only the layers or data types that are relevant to your project in small sections. When you click on "show grid" as you review the options available in your search area, you see the portion of the grid that covers your area of interest. What you don't see is the rest of the grid that extends across our entire coverage area.
Related: The Essential Cheat Sheet For Purchasing Digital Geo Data
How To Use It
The tile indexes are georeferenced vector files in SHP or KML format, one for each metadata group. They can be downloaded for free via the coverage map. These indexes can be loaded in your own software to see the context of where the individual tile boundaries fall in relation to your existing data. You will be able to see at a glance how many tiles you will need to cover your area of interest. And, since each tile in each index has itemID and filename information associated with it, you can select the tiles you want on MapWarehouse directly, using the advanced search.
For Advanced Users
You may also select and export a subsection of an index as a new shape file and forward it to our customer service staff as your ordering polygon when requesting a quote. This method not only helps us get the quote to you quickly, it also allows you to keep the exact boundary of your area of interest confidential. Selecting the tiles you'd like directly from the tile index is also the best way to place a very large order.
Step By Step
1. Go to the MapWarehouse coverage map.
2. Find the metadata group you're interested in. For this example, we'll look at Orthophoto Mapping for Brampton, 10 cm, 2013. Click the magnifying glass to see the coverage of this metadata group highlighted in pink on the interactive coverage map.
3. Choose either KML or SHP format from the icons beside the magnifying glass. Click the icon to download a zip folder containing the index file.
4. For KML format, the zip folder contains a single kml file. Double click the file. Google Earth will launch and draw the tile index in position on the globe.
5. Click any of the tiles in the index to see the file name, a preview, and additional info about the selection.
6. For SHP format, the zip folder contains four files with different extensions that work together to create map feature geometry and associated attributes. Launch ArcGIS and add the SHP file to your map project.
7. The attribute table contains information for each tile in the index file, including file name and itemID, which can be used to locate the tile in the advanced search on MapWarehouse.
8. Export the selected records and save them as a new SHP file to submit them as an ordering polygon.
9. For even better results, subscribe to MapCast to stream imagery and contours directly to your workstation. The photographic detail in the base layer helps you find your area and select tiles quickly and accurately.